Dual hybrid fluid heating apparatus and methods of assembly and operation

ABSTRACT

A dual hybrid heating apparatus, method of assembly and operation to pre-heat vaporizable fluid by free heat sources—waste heat from heat recovery units and insolation. The pre-heated vaporizable fluid is routed to where a parabolic dish solar concentrator vaporizes it to turn a blade of a turbine generator to generate electricity. Heat is extracted from the vapor to form condensate, but the vapor also heats the condensate before being cooled by heat exchange with fluid cooled by a cooling tower.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Ser. No. 13/234,292 filed Sep. 16,2011, which in turn is a continuation-in-part of Ser. No. 12/820,241filed Jun. 22, 2010, whose contents are incorporated herein by referenceand which in turn is a continuation-in-part of U.S. patent applicationSer. No. 12/205,878 filed Sep. 8, 2008, whose contents are incorporatedherein by reference and which in turn claims the benefit of priorityfrom U.S. provisional patent application No. 61/086,819, filed on Aug.7, 2008, the contents of which are hereby incorporated herein byreference, and a continuation-in-part of international patentapplication No. PCT/US2009/049741 filed Jul. 7, 2009, the contents ofwhich are incorporated herein by reference and which in turn claimspriority from U.S. patent application Ser. No. 12/205,878 filed Sep. 8,2008 and provisional patent application Ser. No. 61/086,819 filed Aug.7, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dual hybrid heating apparatus. Theapparatus satisfies a demand for domestic hot water by heating potablewater by heat exchange with a fluid heated from waste heat of at leastone heat recovery unit and with insolation from at least one solarcollector. Once the demand is satisfied, the heated fluid is thenvaporized with a parabolic dish solar concentrator (collector) and fedto a turbine that generates electricity for a power grid. One or morecontrollers direct operation of equipment and in-line valves to operatethe dual hybrid heating apparatus based on sensor readings in a mannerthat satisfies the demand and generates the electricity without damagingthe equipment from overheating.

2. State of the Art

US patent application publication no. 2010003953 and US patentapplication publication no. 20100257882 are known. The former divulges awater heating system for controlling the heating of potable water incommercial or private dwellings with improved energy efficiency. Thewater heating system heats potable water in a tank by transferringexcess heat generated in a refrigeration unit with a heat exchanger, andby extracting energy from insolation with a solar water heater unit. Thesystem includes several control systems for regulating the operation ofthe heat exchanger, solar water heater unit, and refrigeration unit toprovide increased energy efficiency and longevity to the variouscomponents of the system. The latter divulges a hybrid heating apparatusheats potable water with waste heat from heat recovery units andinsolation from solar collectors. A single circulation pump circulatesfluid between at least one heat exchanger and each of the heat recoveryunits and preferably the solar collector. A single controller receivessensor readings from the heat recovery units and the solar collectorunits and receives a demand to heat the potable water. To satisfy thedemand, the controller determines the extent to which the demand may besatisfied from heat available from the heat recovery units and the solarcollector units and sends command signals both to the circulating pumpto circulate the fluid and to appropriate ones of valves at connectionsto those heat recovery units and solar collector units to allow fluid tocirculate to be heated to flow to the heat exchanger for effecting heatexchange to heat the potable water. Once the demand for heated potablewater is satisfied, the fluid from the solar collection units is routedto a heat dump.

SUMMARY OF THE INVENTION

A water heating apparatus is provided to satisfy a demand for heatedpotable water by carrying out heat exchange with the potable water by“free heat” energy sources, i.e., waste heat of at least one heatrecovery unit and insolation of at least one solar heat collection unit.Once the demand is satisfied, the “free heat” sources then pre-heatanother fluid by heat exchange that is to be vaporized with a solarcollector and then fed to a turbine that generates electricity to apower grid.

The at least one heat recovery unit, the at least one solar heatcollection unit, the parabolic dish solar concentrator (collector) andthe heat exchangers each include sensors that measure temperature,pressure, or other parameters at various locations. A controllercontrols their operation based on the measured parameters to maximizethe energy efficiency, hot water capacity, and longevity of the systemwhile reducing the system's operational costs and fuel consumption.

The at least one heat recovery unit recovers waste heat from arefrigeration unit, which preferably includes a fan controller thatoperates to deactivate (turn off) the cooling fan of the refrigerationunit when the refrigerant is sufficiently cooled on account of theoperation of the heat exchanger in transferring heat away from therefrigerant to the water in the tank, and operates to activate (turn on)the cooling fan of the refrigeration unit when additional cooling isneeded.

The heat recovery unit (HRU) preferably includes an HRU controller thatoperates to activate the heat recovery unit to circulate a fluid to heatexchange with “waste heat” that would otherwise be expelled into theatmosphere by a fan blowing across refrigerator/freezer coils thatcontain a refrigerant. To accomplish this, the temperature of the fluidheated with the waste heat must be higher than the temperature of thefluid in the potable water tank and there needs to be a demand forheating the potable water in the potable water tank that is not yetsatisfied (such as where the potable water temperature is under 200degrees Fahrenheit).

The solar heat collection unit preferably includes solar controller thatoperates to activate the solar heat collection unit to circulate thesame fluid (or a different one) that heats from insolation in at leastone solar collector. To accomplish this, heat from insolation must beavailable (8-24 degrees Fahrenheit hotter than the potable watertemperature for efficient heat transfer) and there must be a demand forheating the potable water tank that is not yet satisfied (such as wherethe potable water temperature is under 200 degrees Fahrenheit).

In the event that the demand for heated potable water is satisfied, afurther controller operates a three-way valve to cause the heated fluidto bypass the potable water tank to enter another heat exchanger, wherea fluid (such as water or oil) is heated and conveyed to a locationwhere a parabolic dish solar concentrator (collector) vaporizes thefluid to feed same onto a turbine that generates electricity for a powergrid. Of course, the HRU controller, the solar controller and thefurther controller may all be a single controller that provides all thenecessary commands to all equipment and valves to carry out theirrespective operation in a manner compatible with each other thatprevents overheating or damage to such equipment and valves.

Additional objects, advantages, and embodiments of the invention willbecome apparent to those skilled in the art upon reference to thedetailed description taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depiction of an exemplary embodiment of a waterheating system according to the present invention.

FIG. 2 is a schematic of the circuitry of an embodiment of theoperational control of the fan of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to FIG. 1, the present invention brings together multipleenergy systems to heat fluid in a closed loop either at the same time,consecutively or alternatively with at least one “free heat” energysource—i.e., waste heat from at least one heat recovery unit 16 andinsolation from at least one solar collection unit 18. The heated fluidenters a heat exchanger 60 to satisfy demand to heat potable water. Oncethe demand is satisfied, the heated fluid is routed to another heatexchanger 71 to pre-heat additional fluid (such as water or oil) beingconveyed to a parabolic dish solar concentrator (collector) 80 thatheats the fluid hot enough to transform the fluid into a vapor. Thevapor is fed to a turbine 81A to turn its blades so a generator 81B cangenerate electricity. The vapor discharges at a lower pressure to a heatexchanger 103 to become a condensate after heat extraction that in turnis later heated as part of a liquid-vapor heating cycle. The generatedelectricity is transmitted to a power grid 83. The heat exchanger 103extracts heat from the vapor with fluid cooled by a cooling tower 97.

Preferably, a water heating apparatus or system 110 of the presentinvention is a two-tank system that includes a pre-heat tank 112-1, aconventional heating tank 112-2, and a bypass system 180. Theconventional heating tank 112-2 is in fluid communication with a source14 of potable water such as, but not limited to, a well or a city watersource. The tank 112-1 contains a heat exchanger 60 configured to heatwater stored in the tank 112-1 by heated fluid in communication with aheat recovery unit 16 and a solar water heater unit 18.

The system is configured to heat the potable water in the pre-heat tank112-1 by using heat available from “free” sources (e.g., waste heatrecovery and solar units) in conjunction with the conventional heatingelement 120 to provide an energy efficient hot water heating system 110,a conventional heating tank 112-2, and a bypass system 180. Theconventional heating tank 112-2 includes a conventional heating element120, which may be an electrically powered element, a gas-burningelement, an oil-burning element, and combinations thereof. Thecombination of the pre-heat tank 112-1 with the heating tank 112-2allows the system 110 to maximize the collection and storage of heatfrom the heat recovery unit 16 and the solar water heater or solarcollection unit 18.

The heat recovery unit 16 of the system is in a heat exchangerelationship with a conventional vapor compression refrigeration unit 22such as, but not limited to, an air conditioner, a refrigerator, afreezer, a heat pump, or equivalent refrigeration units known in theart. The heat recovery unit 16 includes a circulating pump 54, whichcirculates fluid medium from the tank 12 through a flow loop 17, a heatexchanger 26, and a controller 58. When heat is available from the vaporcompression refrigeration unit 22, the controller 58 is configured toopen valve 74A and activate the pump 54 to pump the fluid medium fromthe tank 112-1 through the heat exchanger 26 and back into the tank112-1.

The refrigeration unit 22 includes a flow loop 19 for circulatingrefrigerant. A compressor 32 operably coupled to the flow loop 19compresses the refrigerant and passes the compressed refrigerant to acondenser 34. The condenser 34 is also operably coupled to the flow loop19 and includes a cooling fan 36 to force outside air 38 across thecondenser 34 to remove heat from the refrigerant within the flow loop19.

Thus, the refrigeration unit 22 typically consumes electrical energy tooperate the cooling fan 36 to expel waste heat to the outside air 38.The compressed, condensed refrigerant is then expanded in an expansionvalve 40 to a lower temperature, and then passed through an evaporator42. The evaporator 42 includes a blower unit 44, which blows inside air46 from a conditioned space across the evaporator 42. The refrigerationunit 22 thus provides conditioned air to a conditioned space.

The heat exchanger 26 of the heat recovery unit 16 is in heat exchangecommunication with the refrigerant in the flow loop 19 between thecompressor 32 and the condenser 34, which is generally at a hightemperature. The heat exchanger 26 operates to transfer waste heat(which is typically removed from the refrigerant by the fan 36 in theprior art) to the water in tank 12, which will generally be at a lowertemperature than that of the refrigerant between the compressor 32 andthe condenser 34. The heat exchanger 26 includes a first flow path 19 a,which is part of the flow loop 19 of the refrigeration unit 16, and asecond flow path which is part of the flow loop 17 of the heat recoveryunit 16 and in fluid communication with the first flow path 19 a. Theheat recovery unit 16 removes heat from the refrigerant in the flow loop19 of the refrigeration unit 22 and in fluid communication with thepotable water in the tank 12, which also reduces the typical coolingrequirements of the fan 36.

The operation of the controller 58 of the heat recovery unit 16 of thesystem is best understood with reference to FIG. 1. The controller 58opens the valve 74A and activates the circulation pump 54 to circulate afluid medium (heat transfer fluid) from the tank 12 through the heatexchanger 26 when heat is available from the refrigeration unit 22. Forexample, the controller 58 can receive a first sensor input 69indicative of a condition of the refrigerant in the refrigeration unit22 such as, but not limited to, a temperature signal, a pressure signal,or other signals conveying information related to the refrigerant'sproperties. When the first input 69 reaches a predetermined levelindicating that heat is available from the refrigeration unit 22, thecontroller 58 may activate the circulation pump 54.

The controller 58 is also preferably configured to deactivate thecirculating pump 54 to cease circulating fluid medium from the tank 12through the heat exchanger 26 when the water within the tank 12 reachesa predetermined temperature. For example, the controller 58 may receivea second sensor input 68 indicative of the water temperature within thetank 12. When the second sensor input 68 reaches a predetermined level,the controller 58 deactivates the circulation pump 54. In one example,the second sensor input 68 may be a temperature signal and thepredetermined level might be 155 degrees Fahrenheit (F.).

The controller 58 may also be configured to activate the circulatingpump 54 when the temperature of the fluid medium in the second fluidloop 17 becomes so low that it is in danger of freezing. For example, inan Open Loop configuration the controller 58 may receive a first sensorinput 69 indicative of the fluid medium temperature within the secondfluid loop 17. When the first sensor input 69 reaches a predeterminedlevel, the controller 58 activates the circulation pump 24 to circulatewater from the tank 12 through the second fluid loop 17 to preventfreezing therein. It is noted that if the refrigeration unit 22 isoperational, then the circulating pump 54 will operate as discussedabove to transfer heat from the refrigerant to the fluid medium at theheat exchanger 26.

In the event that the refrigeration unit 22 goes down during the wintermonths, the operation of the circulating pump 54 to circulate fluidmedium from the tank 12 through the second fluid loop 17 will help toprevent the fluid medium from freezing in the second fluid loop 17. Itis anticipated that other back-up sources of heat may be utilized withthe system (such as gas or oil) to heat the tank 12 so that the tank 12water will remain warm even during a long power outage. It is alsoanticipated that this anti-freezing operation of the controller 58 willbe far less common, but will provide an important safety measure in thewinter time to prevent the heat recovery unit 16 from freezing andincrease its longevity.

The controller 58 can be embodied by a variety of control circuitry,such as a programmed controller or dedicated hardware logic (PLD, FPGA,ASIC) and supporting circuitry (e.g., thermistors for temperaturesensing or pressure transducers for pressure sensing), one or morerelays and supporting circuitry (e.g., thermostats for temperaturesensing or pressure controllers for pressure sensing) or other suitablecircuitry.

The operational control of the fan 36 of the refrigeration unit 16 isbest understood with reference to FIGS. 1 and 2. A fan control 30 isprovided in the form of a delay relay or controller in electricalcommunication with the fan 36. During normal operation of therefrigeration unit 16, the fan control 30 delays the operation of thefan 36 until a condition within the refrigeration unit 16 reaches apredetermined level. As discussed above, the heat recovery unit 16removes heat from the refrigerant in the flow path 19 a of the flow loop19 of the refrigeration unit 22 that would otherwise need to be removedby the fan 36. Thus, the fan 36 need not be operated until the heatrecovery unit 16 can no longer remove enough heat from the refrigerationunit 22 to keep the refrigeration unit 16 operating in a desired manner.

For example, in medium temperature refrigeration units such as thosepresent in a restaurant, bar, or other commercial establishment, it istypically desired that the refrigerant exiting the condenser 34 be in avapor condition with a desired temperature and/or pressure. The fancontrol 30 receives an input from the refrigeration unit 22, which isindicative of the temperature of refrigerant within the flow loop 19 ofthe refrigeration unit 16. The fan control 30 maintains the fan 36 in anoff condition until the input reaches a predetermined level, at whichtime, the fan control 30 activates the fan 36 to expel heat from therefrigerant to the ambient air 38 at the condenser 34.

In one preferred embodiment, the input is a pressure input from apressure transducer positioned at 52 in the flow loop 19 of therefrigeration unit 22 between the heat exchanger 26 and the condenser34. If the pressure of the refrigerant in the flow loop 19 exceeds apredetermined limit after passing through the heat exchanger 26, theninsufficient heat has been removed from the refrigerant by the heatexchanger 26. Typically, this results from the water in the tank 12being of a sufficiently high temperature from the heat already collectedby the heat recovery unit 16 and/or the solar collection unit 18(further discussed below).

When the pressure of the refrigerant in the flow loop 19 exceeds apredetermined limit after passing through heat exchanger 26, the fancontrol 30 activates the cooling fan 36 to expel waste heat from therefrigerant to the outside air 38. Conversely, when the pressure of therefrigerant in the flow loop 19 is below the predetermined limit afterpassing through heat exchanger 26, the fan control 30 maintains thecooling fan 36 in a normally deactivated state. In embodiments of theinvention in which the refrigeration unit 22 is a medium temperaturerefrigeration unit, the predetermined pressure limit at transducer at 52could be approximately 200 pounds per square inch (PSI).

The controller 30 can be embodied by a variety of control circuitry,such as a programmed controller or dedicated hardware logic (PLD, FPGA,ASIC) and supporting circuitry (e.g., thermistors for temperaturesensing or pressure transducers for pressure sensing), one or morerelays and supporting circuitry (e.g., thermostats for temperaturesensing or pressure controllers for pressure sensing) or other suitablecircuitry. An exemplary embodiment of controller 30 is shown in FIG. 2,which includes a pressure control unit 701 in electrical connectionbetween one leg 702A of line AC and one of the terminals of thecondenser fan 36 as shown. The other terminal of the condenser fan isconnected to the other leg 702B of line AC. A capillary tube 703 is influid communication with the fluid loop 19, preferably at a pointdownstream of the heat recovery unit 26 and upstream of the condenser 34(e.g., preferably at 52 as shown, but may optionally be placed anywherealong the length of the condenser) in order to sample the pressure ofthe refrigerant in the fluid loop 19. The pressure control unit 701measures the sampled pressure of the refrigerant of the fluid loop 19and provides a normally-off current path between leg 702A and theterminal of the condenser fan 36 that is turned on when the sampledpressure reaches a predetermined cut-in pressure. This current path isthen returned to the normally-off state when the pressure falls below apredetermined cut-off pressure. In the preferred embodiment, the cut-inand cut-out pressures are set by user input (for example, by useradjustment of dials for setting such cut-in and cut-out pressures). Inthe preferred embodiment, the pressure control unit 701 is realized by aunit (e.g., the 016 Single Pressure Control unit) sold commercially byRanco Controls of Delaware, Ohio.

Thus, system 110, through the operation of the fan control 30 of therefrigeration unit 22, maximizes the amount of heat recovered by theheat recovery unit 16 by eliminating the expulsion of heat from therefrigerant to the ambient air when such expulsion not needed. Further,system 110 minimizes energy usage by leaving fan 36 in a normally “off”state until such time as the heat recovery unit 16 no longer hassufficient capacity to remove enough heat from the refrigerant in theflow loop 19 to keep the refrigeration unit 22 operating as desired.

The system 110 of the present invention also preferably incorporates inone fluid medium loop of a hybrid water heating system, the solar waterheater unit 18, and uses it in conjunction with the heat recovery unit16. The solar water heater unit 18 and HRU 16 and its operationalcontrol is best understood with reference to FIG. 1.

The solar collection unit 18 provides heat captured from solar energy tothe water in the tank 12. Thus, the water in tank 112-1 is heated notonly by the heat recovery unit 16, but also by the solar collection unit18. The fan control 30 protects the refrigeration unit 22 from damagedue to overheating and maintains the refrigeration unit 22 in a desiredoperating condition when a large amount of heat is added to the water inthe tank 112-1 by both the heat recovery unit 16 and solar collectionunit 18 thru one Solar and HRU fluid medium Loop.

The solar collection unit 18 includes a circulating pump 54, whichcirculates a heat transfer medium through a flow loop 17. A solarcollector 56 and a heat exchanger 60 are operably coupled to the flowloop 17 as shown in FIG. 1. A controller 58 is provided for opening thevalve 74B and for selectively activating and deactivating thecirculating pump 54 of the solar collection unit 18. When heat isavailable from insolation by the solar collection unit 18, thecontroller 58 is configured to open the valve 74B and to activate thecirculating pump 54 to pump a heat-transfer fluid such as, but notlimited to, propylene glycol through the solar collector 56 and the heatexchanger 60 via the fluid loop 17. The solar collector 56 thus heatsthe heat-transfer fluid, and the heat from the heat-transfer fluid isused to indirectly heat the water in the tank 112-1 via the heatexchanger 60.

The controller 58 may be directed to open just one of the valves 74A or74B at any one time (depending upon the availability of heat from the“free heat” sources) or both valves 74A and 74B at the same time so thatboth “free heat” sources may contributed to heating together. Thecontroller 58 adjusts the speed of the pump accordingly. There is also a3-way valve 72 that normally directs fluid to heat exchanger 60 withinthe tank 112-1. Check valves 73A, 73B, 73C are provided to preventbackflow. When tank temperature is above 185 degrees Fahrenheitcontroller 58 activates the 3-way valve 72 to alter the flow path so asto route the fluid instead to heat exchanger 71 (outside the tank) untilthe tank temperature is below 175 degrees Fahrenheit. The heat exchanger71 than preheats fluid (water or oil) that is to be vaporized by theparabolic dish solar concentrator 80 and fed to the turbine-generator 81that generates electricity for the grid 83.

The fluid loop 17 of the solar collection unit 18 and HRU 16 is shown(FIG. 1) by way of example as an indirect or closed-loop circulationsystem where the circulating pump 54 circulates the heat-transfer fluidthrough the solar collector 56 and HRU 16 in fluid communication withthe heat exchanger 60 to indirectly heat the water in the tank 12.However, the solar collection unit 18 may also be a direct or open-loopcirculation system in which the pump 54 circulates the potable waterfrom the tank 12 directly through the solar collector 56 and HRU 16 backinto the tank 12.

Conversely, while the fluid loop 17 of the heat recovery unit 16 isshown (FIG. 1) by way of example as a indirect or closed-loopcirculation system where the pump 54 circulates the fluid medium fromthe tank 12 through the heat exchanger 26 and back into the tank 12, thefluid loop 17 may instead be an indirect or closed-loop circulationsystem isolated from the water in the tank 12 in which the pump 54circulates a heat-transfer fluid through the heat exchanger 26 andthrough an additional heat exchanger 60 in a heat exchange relationshipwith the water in tank 12 to indirectly heat the water in the tank.

In addition, the heat exchanger 60 disposed at the tank 12 is shown byway of example only as a flat heat exchanger in tank 12. However, it iscontemplated that the heat exchanger 60 may be any device sufficient toplace the heat-transfer fluid of the solar collection unit 18 in a heatexchange relationship with the water in the tank 112-1. The tank 112-1may also be a jacketed tank in which the heat exchanger 60 forms a heatexchange jacket around the outer surface of the tank 112-1.

The solar collector 56 can be any device sufficient to collect heat fromsolar energy. For example, the solar collector 56 can be a glazedflat-plate collector, an un-glazed flat-plate collector, anevacuated-tube solar collector, a photo-voltaic module, a drain-backsystem, and any combinations thereof.

The term “glazed flat-plate collectors” used herein refers to collectorshaving an insulated, weatherproofed box that contains a dark absorberplate under one or more glass or plastic covers. The term “unglazedfiat-plate collectors” used herein refers to collectors having a darkabsorber plate, made of metal or polymer, without a cover or enclosure.The term “evacuated-tube solar collectors” used herein refers tocollectors having parallel rows of transparent glass tubes where eachtube contains a glass outer tube and a metal absorber tube attached to afin. The fin's coating absorbs solar energy but inhibits radiative heatloss. The term “photo-voltaic module” used herein refers to collectorshaving an array of photo-voltaic cells that convert solar energy intoelectrical potential. The electrical potential can be used to providecurrent to an electrical heating element, which heats the water in thetank 112-1.

The controller 58 of the solar water heater unit 18 controls thecirculating pump 54 to circulate the heat-transfer fluid from the heatexchanger 60 in the tank 112-1 through the solar collector 56 only whenheat is available at the solar collector 56. For example, the controller58 may receive an input 66 indicative of a condition of the solarcollector 56. The input 66 may include, but is not limited to, atemperature signal indicative of the temperature of the heat-transferfluid at the solar collector 56. When the input 66 reaches apredetermined limit indicating that sufficient heat is available fromthe solar collector 56, the controller 58 activates the circulation pump54.

The controller 58 is preferably configured to activate the circulatingpump 54 to cease circulating the heat-transfer fluid through the solarcollector 56 and the heat exchanger 60 when the water within the tank 12reaches a predetermined temperature. For example, the controller 58 canreceive an input from sensor 68 that is indicative of a temperature ofthe water within the tank 112-1. When the input from the sensor 68reaches a predetermined limit, the controller 58 deactivates thecirculating pump 54. The circulating pump 54 can be an electricallypowered pump, powered by a standard 115-volt power source. The pump 54may also be powered by electricity collected by a photo-voltaic solarcollector (not shown).

The controller 58 is described by way of example as operating based on atemperature limit (e.g., input from a sensor 66) and a temperature limit(e.g., input from the sensor 68). However, the controller 58 may alsooperate as a differential controller in which the controller 58activates the circulating pump 54 when the inputs from sensors 66, 68are indicative of a temperature differential of at least a predeterminedvalue. For example, the controller 58 can be configured to activate thecirculating pump 54 when the sensed inputs from sensors 66, 68 areindicative of at least approximately 8 degrees Fahrenheit (F.) and candeactivate the pump when the temperature differential is less thanapproximately 8 degrees Fahrenheit (F.). Similarly, the controller 58 ofthe heat recovery unit 16 (FIG. 1) may be configured to operate as adifferential controller in which the controller 58 only activates thecirculating pump 54 when the inputs from sensors 69/68 are indicative ofat least a predetermined value. The controller 58 can also operate todeactivate the circulating pump 54 upon the input from sensor 66 exceedsa temperature limit indicative that the solar collector is at a maximumtemperature for preventing damage to system components. A relief valve(not shown) is operably coupled to the flow loop 17 for lowering thepressure within the flow loop 17 in the event that the input from thesensor 66 exceeds the temperature limit. In an open configuration of therelief valve, the second heat transferring medium is drained from theflow loop 17 in gas or liquid form to lower the pressure therein.

The controller 58 can be embodied by a variety of control circuitry,such as a programmed controller or dedicated hardware logic (PLD, FPGA,ASIC) and supporting circuitry (e.g., thermistors for temperaturesensing or pressure transducers for pressure sensing), one or morerelays and supporting circuitry (e.g., thermostats for temperaturesensing or pressure controllers for pressure sensing) or other suitablecircuitry. In an exemplary embodiment, the controller 58 is realized bya programmed controller adapted for differential temperature control ofsolar energy systems, such as the Resol module.

When heat is unavailable from either the heat recovery unit 16 or thesolar collection unit 18, the system 10 utilizes a conventional heatingelement 120 to heat the water in the tank 12. Heating element 20 may bean electrically powered element, a gas-burning element, an oil-burningelement, and combinations thereof.

The hybrid hot water heat system 110 of the present invention thuscombines three heating sources, two of which are available withoutconsuming additional energy. Additionally, the fan control 30 of thehybrid hot water heat system 110 of the present invention selectivelyactivates and deactivates the fan 36 of the vapor compressionrefrigeration unit 22 to minimize the available heat expelled to theambient air 38. The fan control 30 also maximizes the amount of heatrecovered by the heat recovery unit 16 and minimizes the amount ofenergy used while protecting the vapor compression refrigeration unit 22from being damaged.

The bypass system 180 allows a user to divert incoming water from thewater source 14 to bypass the pre-heating tank 112-1 to flow directlyinto the heating tank 112-2. In the illustrated embodiment of FIG. 1,the bypass system 180 includes a first valve 182, a second valve 184,and a third valve 186, each being a two-way valve having an open stateand a closed state. When an operator desires the use of the pre-heatingtank 112-1, the first and second valves 182, 184 can be moved to theopen state while the third valve 186 is moved to the closed state. Inthis configuration, water from the water source 14 flows through thefirst valve 182 into the pre-heat tank 112-1 and from the pre-heat tank112-1 to the heating tank 112-2 through the second valve 184.

Conversely, when an operator desires to bypass pre-heating tank 112-1,the first and second valves 182, 184 can be moved to the closed statewhile the third valve 186 is moved to the open state. In thisconfiguration, water from the water source 14 flows through the thirdvalve 186 directly into the heating tank 112-2 without passing throughpre-heating tank 112-2.

The bypass system 180 is described above by way of example as a manuallyactivated system in which the operator moves the valves 182, 184, 186between the open and closed states. However, it is contemplated that thevalves of bypass system 180 may be automatically controlled between theopen and closed states based on the availability of heat from either theheat recovery unit 16 or the solar collection unit 18.

Additionally, the bypass system 180 is described above by way of examplewith respect to the three separate two-way valves 182, 184, and 186.However, it is contemplated that the bypass system 180 may include anycombination of valves sufficient to selectively place the pre-heatingtank 112-1 in fluid communication with the water source 14 and theheating tank 112-2. For example, it is contemplated that the bypasssystem 180 may include one three-way valve that replaces the first andthird valves 182, 186.

When the temperature in the pre-heating tank 112-1 reaches 160 degreesFahrenheit, valves 74A and 74B may remain open as long as there is heatavailable from them. The controller 58 activates the three-way valve 72to route the fluid to the heat exchanger 71 instead of the pre-heatingtank 112-1 and directs a driver of the pump 82 to pump at a flow rate(perhaps higher than before) since heat exchange will be available topre-heat the further fluid (water or oil) passing through the heatexchanger 71, provided the sensor 85 by the parabolic dish solarconcentrator (collector) 80 senses a temperature above 220 degreesFahrenheit. Such activation is carried out by issuing appropriatecommand signals to drivers for those valves.

When the sensor 85 by the parabolic dish solar concentrator (collector)80 senses a temperature above 220 degrees Fahrenheit even though thedemand for heated potable water at the pre-heating tank 112-1 has notyet been satisfied, the controller 58, which received the sensedtemperature measurement, sends command signals to the pump 82 to pumpthe further fluid to the parabolic dish solar collector 80 (perhaps at alower flow rate than would be the case if the demand were satisfied) tovaporize the fluid such as to produce steam where the fluid is water.The vaporized fluid is fed to a turbine generator 81 to turn the turbineblades to produce electricity, which is transmitted to the power grid 83via electrical connections. Note that the heating of the potable waterin the pre-heating tank 112-1 is essentially independent of whattranspires at the parabolic dish solar collector 80, which is why theparabolic dish solar collector should be vaporizing the fluid ifconditions are suited to do so. That process just becomes more efficientafter the demand for heating of the potable water is satisfied, becausethe fluid becomes pre-heated by heat exchange at heat exchanger 71before the fluid reaches the parabolic dish solar collector 80.

The flow rate set for the pump 82 should be varied by the controller 58in dependence upon the sensed temperature of the further fluiddownstream of the further heat exchanger 71. For instance, if thefurther fluid is not being pre-heated at the further heat exchanger 71(perhaps because the demand for heating potable water at the tank 112-1is not satisfied), then the temperature of the further fluid will belower than would otherwise be the case prior to reaching where sensor 85detects the temperature imparted by the parabolic dish solarconcentrator (collector) 80 that concentrates solar radiation. As aresult, the temperature differential between the further fluidtemperature and the boiling point of the further fluid is greater thanwould be the case if pre-heating were available and thus thevaporization rate will be slower (i.e., as to the vaporization capacityor the amount of the further fluid that can be vaporized over time). Onthe other hand, if the further fluid is pre-heated by the further heatexchanger 71 (as would be the case where the at least one free energysource is generating heat and the demand for heating the potable waterin the tank 112-1 is satisfied), the temperature differential requiredto be met to effect the vaporization will be smaller so that thevaporization rate will be faster for the same flow rate than when thereis no pre-heating of the further fluid at the further heat exchanger.Even so, thanks to the heat exchange at the heat exchanger 105, thereshould be some realization of elevation in the temperature of thecondensate at all times that electricity is being generated and therebythe further fluid entering the further heat exchanger 71 will be at thathigher temperature. Thus, there will be a smaller temperaturedifferential that needs to be met to effect vaporization of the furtherfluid. However, the pre-heating of the further fluid at the further heatexchanger, when available, should lessen the temperature differentialstill further (if the flow rate stays the same). As a result, thecontroller 58 may change the flow rate of the further fluid accordinglyto match the capacity for vaporizing the further fluid by the parabolicdish solar concentrator (collector) 80 (i.e., to handle a greater flowrate of the further fluid).

The controller 58 may take into account measurements of at least oneparameter by sensors suitably arranged to take such measurements. Forinstance, the measurements may be that of fluid temperature, infraredradiation wavelength emanating from the fluid, and/or fluid pressure.

In one aspect, the invention resides in a dual hybrid fluid heatingapparatus (method of assembly and method of operation); comprising:equipment that includes a pump, a tank, at least one free heat energysource, a parabolic dish solar concentrator and a turbine generator, theat least one free heat energy source being selected from the groupconsisting of at least one waste heat recovery unit and at least onesolar collector unit; drivers of the equipment and associated valvesthat affect flow through piping; and at least one controller 58 withlogic that makes determinations based on sensor readings to issueappropriate command signals to the drivers, the sensor readings beingselected from a group consisting of an extent of heat exchange by a tankheat exchanger within the tank, an extent of heat exchange by a furtherheat exchanger, an extent of fluid vaporization, the drivers beingresponsive to receipt of the appropriate command signals to:

-   -   (a) circulate fluid between the at least one free energy source        and the tank heat exchanger provided the extent of heat exchange        by the tank heat exchanger signifies that a demand for heating        potable water within the tank is unsatisfied according to the        determinations;    -   (b) circulate the fluid between the at least one free energy        source and a further heat exchanger so as to bypass the tank        heat exchanger and heat a further fluid by heat exchange with        the circulating fluid provided the extent of heat exchange by        the tank heat exchanger signifies that the demand is satisfied        according to the determinations;    -   (c) divert the fluid to a heat dump provided the extent of heat        exchange by the further heat exchanger signifies that        temperature downstream of the further heat exchanger attained a        threshold level according to the determinations; and    -   (d) circulate the further fluid at a flow rate set by the        controller to pass through the further heat exchanger and then        to a location where heat imparted from concentrated solar        radiation reflecting off a parabolic dish solar concentrator        vaporizes the further fluid into a vapor that enters a turbine        generator to turn a blade causing the turbine generator to        generator electricity to a power grid and after which leave the        turbine generator to condense into a liquid from heat        extraction, the controller setting the flow rate based on a        determination that takes into account a sensed parameter of the        further fluid downstream of the further heat exchanger and on a        sensed extent of vaporization of the further fluid from the        solar radiation reflecting off the parabolic dish solar        concentrator; and    -   (e) circulate an additional fluid at a further flow rate between        a cooling tower and an additional heat exchanger that effects        the heat extraction of the vapor and blowing air into the        cooling tower with the cooling tower fan to cool the additional        fluid heated by the heat extraction, the controller setting the        further flow rate based on making a determination that takes        into account an extent of the heat extraction and setting a        speed of a cooling tower fan that blows air into the cooling        tower to cool the additional fluid based on the determination        that takes into account the extent of the heat extraction.

Preferably, an appliance is selected from the group consisting of arefrigerator, a freezer, a refrigerator-freezer, a walk-in refrigeratorand a walk-in freezer. The at least one waste heat recovery unitrecovers waste heat from the appliance.

Electrical connections are arranged to enable the transfer of theelectricity to the power grid. The making of the determinations by thecontroller on varying the rate of flow of the further fluid is alsobased on detection of whether the electrical connections are suited totransfer the electricity to the power grid. For instance, if the powergrid is down (black-out) or the electrical connections are undergoingmaintenance, then signals would be sent to the controller signifyingthat the transfer of electricity generation is not feasible. Theelectrical connections may include a disconnect switch that would bethrown to disconnect from the power grid during maintenance periods.

Sensors are arranged to measure at least one parameter—i.e., selectedfrom the group consisting of temperature, pressure and infraredradiation wavelength. The controller is arranged to receive the at leastone measured parameter from the sensors and issues the command signalsbased in part on the at least one measured parameter.

Once the vapor finishes turning a blade of the turbine 81A of theturbine-generator 81, the vapor, now at a lower pressure, is routed to aheat exchanger 105 within a pre-heater tank 87 where the fluid in thepre-heater tank 87 is heated through the extraction of heat form the lowpressure vapor. The low pressure vapor may partially transform into alow pressure vapor/liquid mix after emerging from the heat exchanger105, but flows by gravity down to heat exchanger 103, which it istransformed into condensate due to heat exchange by the heat exchanger103.

To help ensure that the low pressure vapor/liquid mix is transformedinto condensate, a cooling tower 97 is employed to cool fluid that ispumped by pump 101 to circulate through the heat exchanger 103 toextract heat from the low pressure vapor/liquid, thereby transformingthe mix into condensate. A fan is driven by a motor driver 95 to blowair through the cooling tower to cool the heated fluid leaving the heatexchanger 103 that is pumped by the pump 101. Sensors 93 and 99 measurethe temperature (or pressure) in the cooling tower 97 and the fluidbeing pumped, respectively, to transmits the measurements to thecontroller 58. The controller 58 then directs the motor driver 95 of thecooling tower fan and the motor driver of the circulating pump 101 toset their speeds.

For example, if the demand to heat potable water in the tank 112-1 hasnot been satisfied, then there may be less pre-heating available at heatexchanger 71 that would be the case if the demand was satisfied. As aconsequence, there is less pre-heated fluid reaching the parabolic dishsolar collector 80 for vaporization and thus potentially less availablevapor produced over time to turn the turbine blades of the turbine 81Athan would otherwise be the case if the demand was satisfied. As aconsequence, the amount of vapor requiring cooling over time is less atthe time it reaches the heat exchanger 103 and thus less heat needs tobe extracted over time to be cooled by the cooling tower 97 than if thedemand were satisfied. With less cooling needs, the cooling tower fanand the pump 103 may run at a slower speed in comparison to when thevapor is produced at maximum capacity (such as when the demand forheating potable water is satisfied, the waste recover unit 16 isextracting waste heat and the solar collection unit 56 and the parabolicdish solar concentrator are receiving insolation).

The condensate is then circulated by pump 82 back to the heat exchanger75 to be heated, but only after the condensate is preheated by heatexchange at heat exchanger 105. Should there be any build-up of vapor inthe tank 87, a pressure relief valve is provided at the top of tank 87to provide the pressure relief. This is done before the vapor isdirected to the heat exchanger 103, where the cooling fan 97 cools thevapor back into condensate.

While the present disclosure has been described with reference to one ormore exemplary embodiments, it is not intended that the invention belimited thereto, and it will be understood by those skilled in the artthat various changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the presentdisclosure. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the disclosurewithout departing from the scope thereof. Therefore, it is intended thatthe present disclosure not be limited to the particular embodiment(s)disclosed as the best mode contemplated, but that the disclosure willinclude all embodiments.

In another aspect, the invention resides in a dual hybrid fluid heatingapparatus, a method of assembling the dual hybrid fluid heatingapparatus and a process of operating the dual hybrid fluid apparatus.The dual hybrid fluid heating apparatus may have at least one controller58 equipped with

-   -   (a) heat availability logic that determines whether heat from at        least one free energy source is or is not available for heat        exchange and, if so, issues appropriate commands to effect the        heat exchange; and    -   (b) vaporization viability logic that determines whether        vaporization of vaporizable fluid is viable with concentrated        solar ration from at least one parabolic dish solar concentrator        and, if so, issues appropriate command signals to heat the        vaporizable fluid with heat from the heat exchange to pre-heat        the vaporizable fluid and to thereafter vaporize the pre-heated        vaporizable fluid into a vapor by concentrated solar radiation        from the at least one parabolic dish solar concentrator up to an        extent of viability.

Preferably, the at least one controller 58 is equipped also with heatextraction logic that determines whether heat extraction from the vaporis viable and, if so, to issue appropriate command signals to extractthe heat from the vapor to transform the vapor into a condensate and tothereafter heat the condensate with the extracted heat. The at least onecontroller 58 may have additional logic that issues additionalappropriate command signals that cause an additional fluid to circulateat a flow rate between a cooling tower and an associated heat exchangerand to cool the additional fluid within the cooling tower by forced airblown from a cooling tower fan into the cooling tower. The at least onecontroller 58 sets the flow rate and sets a speed of the cooling towerfan.

What is claimed is:
 1. A dual hybrid fluid heating apparatus;comprising: at least one controller equipped with (a) heat availabilitylogic that determines whether heat from at least one free energy sourceis or is not available for heat exchange and, if so, issues appropriatecommands to effect the heat exchange; and (b) vaporization viabilitylogic that determines whether vaporization of vaporizable fluid isviable with concentrated solar ration from at least one parabolic dishsolar concentrator and, if so, issues appropriate command signals toheat the vaporizable fluid with heat from the heat exchange to pre-heatthe vaporizable fluid and to thereafter vaporize the pre-heatedvaporizable fluid into a vapor by concentrated solar radiation from theat least one parabolic dish solar concentrator up to an extent ofviability.
 2. The dual hybrid fluid heating apparatus of claim 1,wherein the at least one controller is equipped also with heatextraction logic that determines whether heat extraction from the vaporis viable and, if so, to issue appropriate command signals to extractthe heat from the vapor to transform the vapor into a condensate and tothereafter heat the condensate with the extracted heat.
 3. The dualhybrid fluid heating apparatus of claim 1, wherein the at least onecontroller is equipped also with heat extraction logic that determineswhether heat extraction from the vapor is viable and, if so, to issueappropriate command signals to extract the heat from the vapor totransform the vapor into a condensate, further comprising additionallogic that issues additional appropriate command signals that cause anadditional fluid to circulate at a flow rate between a cooling tower andan associated heat exchanger and to cool the additional fluid within thecooling tower by forced air blown from a cooling tower fan into thecooling tower, the at least one controller setting the flow rate andsetting a speed of the cooling tower fan.
 4. The dual hybrid fluidheating apparatus of claim 1, wherein the at least one free energysource is at least one heat recovery unit of an appliance selected fromthe group consisting of an air conditioner, a heat pump, a refrigerator,a freezer, a refrigerator-freezer, a walk-in refrigerator and a walk-infreezer, the at least one waste heat recovery unit recovering waste heatfrom the appliance.
 5. The dual hybrid heating apparatus of claim 3,further comprising another heat exchanger arranged upstream and at ahigher elevation than the associated heat exchanger so that the vaporheat exchanges with the condensate within the another heat exchangerbefore entering the associated heat exchanger.
 6. The dual hybridheating apparatus of claim 1, further comprising the at least one freeenergy source, the at least one free heat energy source being selectedfrom the group consisting of at least one waste heat recovery unit andat least one solar collector unit.
 7. The dual hybrid heating apparatusof claim 1, further comprising a turbine generator having a blade, aparabolic dish solar concentrator arranged to concentrate the solarradiation at a location to form the vapor from the vaporizable fluid;means for feeding the vapor to turn the blade of the turbine generatorto effect electricity generation into a power grid; means fordischarging the vapor from the turbine generator to condense the vaporinto the condensate by the heat extraction in an associated heatexchanger; and another heat exchanger arranged upstream and at a higherelevation than the associated heat exchanger so that the vapordischarged from the turbine generator heat exchanges with the condensatewithin the another heat exchanger before the vapor discharged enters theassociated heat exchanger.
 8. A method of assembling a dual hybrid fluidheating apparatus, comprising: equipping at least one controllerequipped with (a) heat availability logic to determine whether heat fromat least one free energy source is or is not available for heat exchangeand, if so, issues appropriate commands to effect the heat exchange; and(b) vaporization viability logic to determine whether vaporization ofvaporizable fluid is viable with concentrated solar ration from at leastone parabolic dish solar concentrator and, if so, issues appropriatecommand signals to heat the vaporizable fluid with heat from the heatexchange to pre-heat the vaporizable fluid and to thereafter vaporizethe pre-heated vaporizable fluid into a vapor by concentrated solarradiation from the at least one parabolic dish solar concentrator up toan extent of viability.
 9. The method of claim 8, further comprisingequipping the at least one controller also with heat extraction logic todetermine whether heat extraction from the vapor is viable and, if so,to issue appropriate command signals to extract the heat from the vaporto transform the vapor into a condensate and to thereafter heat thecondensate with the extracted heat.
 10. The method of claim 8, furthercomprising equipping the at least one controller also with heatextraction logic to determine whether heat extraction from the vapor isviable and, if so, to issue appropriate command signals to extract theheat from the vapor to transform the vapor into a condensate, furthercomprising equipping the at least one controller with further logic toissue additional appropriate command signals to cause an additionalfluid to circulate at a flow rate between a cooling tower and anassociated heat exchanger and to cool the additional fluid within thecooling tower with forced air blown from a cooling tower fan into thecooling tower, the at least one controller setting the flow rate andsetting a speed of the cooling tower fan.
 11. The method of claim 8,further comprising selecting the at least one free heat energy sourcefrom the group consisting of at least one waste heat recovery unit andat least one solar collector unit, equipping the at least one controllerto send out appropriate command signals to pre-heat the vaporizablefluid by heat exchange in the further heat exchanger prior to thevaporizing.
 12. The method of claim 8, further comprising arranging aturbine generator having a blade; arranging a parabolic dish solarconcentrator to concentrate the solar radiation at a location to formthe vapor from the vaporizable fluid; arranging a means for feeding thevapor to turn the blade of the turbine generator to effect electricitygeneration into a power grid; arranging a means for discharging thevapor from the turbine generator to condense the vapor into thecondensate by the heat extraction in an additional heat exchanger; andarranging another heat exchanger upstream and at a higher elevation thanthe additional heat exchanger so that the vapor discharged from theturbine generator heat exchanges with the condensate within the anotherheat exchanger before the vapor discharged enters the additional heatexchanger.
 13. The method of claim 8, further comprising selecting, asthe at least one free energy source, at least one heat recovery unit ofan appliance from the group consisting of an air conditioner, a heatpump, a refrigerator, a freezer, a refrigerator-freezer, a walk-inrefrigerator and a walk-in freezer, the at least one waste heat recoveryunit recovering waste heat from the appliance.
 14. A process ofoperating a dual hybrid heating apparatus, comprising operating at leastone controller equipped with (a) heat availability logic that determineswhether heat from at least one free energy source is or is not availablefor heat exchange and, if so, issues appropriate commands to effect theheat exchange; and (b) vaporization viability logic that determineswhether vaporization of vaporizable fluid is viable with concentratedsolar ration from at least one parabolic dish solar concentrator and, ifso, issues appropriate command signals to heat the vaporizable fluidwith heat from the heat exchange to pre-heat the vaporizable fluid andto thereafter vaporize the pre-heated vaporizable fluid into a vapor byconcentrated solar radiation from the at least one parabolic dish solarconcentrator up to an extent of viability.
 15. The process of claim 14,further comprising selecting the at least one free heat energy sourcefrom the group consisting of at least one waste heat recovery unit andat least one solar collector unit.
 16. The process of claim 14, furthercomprising concentrating solar radiation from a parabolic dish solarconcentrator at the location to form the vapor from the vaporizablefluid; feeding the vapor to turn a blade of a turbine generator toeffect electricity generation into a power grid; discharging the vaporfrom the turbine generator to condense the vapor into the condensate bythe heat extraction in an associated heat exchanger; and, before thedischarged vapor enters the associated heat exchanger, heat exchangingthe discharged vapor with the condensate within another heat exchangerthat is upstream and at a higher elevation than the associated heatexchanger.
 17. The process of claim 14, further comprising equipping theat least one controller also with heat extraction that determineswhether heat extraction from the vapor is viable and, if so, to issueappropriate command signals to extract the heat from the vapor totransform the vapor into a condensate, further comprising equipping theat least one controller with further logic to issue additionalappropriate command signals to cause an additional fluid to circulate ata flow rate between a cooling tower and an associated heat exchanger tocool the additional fluid within the cooling tower by forced air blownfrom a cooling tower fan into the cooling tower, the at least onecontroller setting the flow rate and setting a speed of the coolingtower fan.
 18. The process of claim 14, further comprising selecting, asthe at least one free energy source, at least one heat recovery unit ofan appliance from the group consisting of an air conditioner, a heatpump, a refrigerator, a freezer, a refrigerator-freezer, a walk-inrefrigerator and a walk-in freezer.